1. Field of the Invention
The present invention relates to the composition containing the polymer, solvent and a functional substance, the composition being useful as various functional materials. In particular, the present invention relates to an image-forming material useful for printers and displays, in which the composition is an aqueous dispersion material, manufacturing method thereof, and image forming method and image forming device therewith.
2. Description of Related Art
The aqueous dispersion materials containing a granular solid have been previously well known as functional materials, for example, agricultural chemicals such as a herbicides and insecticides; medicines such as antitumor substances, antiallergic drugs, and anti-inflammatory agents; coloring materials such as ink and toners. In recent years, as personal computers become less expensive and more sophisticated and as graphical user interface environment are standardized, it becomes more necessary to achieve a recording method with high vividity, high quality, high fastness, high resolution and high speed. In response to the above, the digital printing technique has been improved with extraordinary momentum. Representative examples of the digital printing technique include electrophotography and inkjet technique. The digital printing technique becomes more and more important as an image formation technique in office, home etc. in recent years.
Among the above, the inkjet technique is a direct recording method which has significant features such as compactness and a low power consumption. Moreover, the inkjet technique has rapidly progressed in image quality by the miniaturization of a nozzle etc. An example of an inkjet technique is a method comprising: evaporating and foaming the ink which is supplied from the ink reservoir, by heating with a heater in a nozzle to eject the ink; and forming an image on a recording medium. Another example is the methods of ejecting ink from a nozzle by vibrating a piezo-electric element. Since an aqueous solution of dyes is usually used as the ink for these methods, there are cases where bleeding arises at the time of the superposition of colors, or the phenomenon referred to as “feathering” running in the direction of fiber in the paper may occur at the recorded point of the recording medium. Application of pigment-dispersed ink has been examined in order to improve them (please see, for example, U.S. Pat. No. 5,085,698). However, it is still true that much improvement is desired.